NASA Robot to Explore 'Bottomless' Pit

by SPACE.com Staff | May 15, 2007 10:12am ET

A robotic yellow
submarine will journey this week to the world's deepest sinkhole, which already
has taken the life of one diver who sought to reach its bottom and discover the
life that might exist there.

Others have
tried to reach the end of this seemingly bottomless pit in the Mexican state of Tamaulipas, known to be at least 925 feet
deep, but no one has ever succeeded.

The self-automated
"DEPTHX"
(Deep Phreatic Thermal Explorer) will search the depths of the El Zacaton
cenote, or geothermal sinkhole, for life and also study its dimensions and look
for the vents that feed it.

NASA, which
funded the robotic explorer, views the mission as a test-run for a potential journey
to Europa, a moon of Jupiter thought to contain liquid water beneath miles of
ice--and possibly complex forms of life. New technologies that could help
explore its ocean will be put to the test during the robot's descent.

"We'll
spend the first two days checking out DEPTHX's sensors, updating its software
and performing a test dive to 250 meters [820 feet] to check its pressure
housings," said David Wettergreen, who helped create the 8-foot-long submarine.

Once the vessel
passes it final exams, Wettergreen and his team will have six days to probe the
sinkhole's watery depths. "It's an ambitious program," Wettergreen said, "but
the vehicle performed well in two earlier field tests at the La Pilita cenote,"
another Mexican sinkhole.

Software
written by Carnegie Mellon University's Robotics Institute will allow the
untethered sub to navigate in the sometimes closely confined underwater spaces
and probe the pitch-black sinkhole with 56 sonar sensors for mapping.

The
progress of DEPTHX, as it gathers water and stone samples from the cenote's
walls, can be monitored at the mission's Web site starting today.

DEPTHX also
will be used to explore two other
sinkholes, Caracol and Verde, during the team's two-week expedition.